Upgrade versions of vendored libs

vendor/github.com/DataDog/zstd/cpu.h

@@ -1,5 +1,6 @@
+#ifndef USE_EXTERNAL_ZSTD
 /*
- * Copyright (c) 2018-present, Facebook, Inc.
+ * Copyright (c) Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
@@ -16,8 +17,6 @@
  * https://github.com/facebook/folly/blob/master/folly/CpuId.h
  */
 
-#include <string.h>
-
 #include "mem.h"
 
 #ifdef _MSC_VER
@@ -213,3 +212,5 @@ MEM_STATIC ZSTD_cpuid_t ZSTD_cpuid(void) {
 #undef X
 
 #endif /* ZSTD_COMMON_CPU_H */
+
+#endif /* USE_EXTERNAL_ZSTD */